Assessment of Agricultural Workers' Exposure Due to Crop Harvesting Operations Within the Areas Affected by Radioactive Contamination.

Implementation of field experiments took place in two sites located in the Bragin district of the Gomel region, Belarus, i.e. a field in the evacuation zone and a private plot of land in a residential area of thedistrict.

Production of protein kinase C-delta by the baculovirus-insect cell system in serum-supplemented and serum-free media.

When rat protein kinase C-delta (PKC-delta) was produced by Sf9 cells infected with a recombinant baculovirus in shake-flask culture using a serum-containing medium, the intracellular PKC-delta content decreased in the late period while the extracellular PKC-6 markedly increased. During the late period of serum-free culture, the extracellular PKC-6 level considerably declined, but the addition of a protease inhibitor, leupeptin, prevented the reduction in PKC-delta production.

Production of recombinant protein by baculovirus-infected insect cells in immobilized culture using porous biomass support particles.

Immobilization of insect cells using porous biomass support particles (BSPs) and production of a recombinant protein by the immobilized cells after infection with a baculovirus were investigated in a shake-flask culture. Sf9 cells were passively immobilized in reticulated polyvinyl formal (PVF) resin BSPs (2 x 2 x 2 mm cubes) with matrices of 60 mum mean pore diameter in situ in shake-flasks. The cell density in the BSPs was over 5 x 10(7) cells/cm3-BSP in cultures with regular replacement of the culture medium, as estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Optimal production of recombinant protein by the baculovirus-insect cell system in shake-flask culture with medium replacement.

Sf9 insect cells infected with a recombinant baculovirus expressing beta-galactosidase and suspended in fresh medium (TNM-FH supplemented with 10% fetal bovine serum) at the time of infection were cultured in shake flasks at various combinations of initial cell density and multiplicity of infection (MOI). The effects of cell density and MOI on beta-galactosidase production were quantitatively analyzed by plotting the beta-galactosidase yield against the time integral of the viable cell density from the time of infection to the time when the beta-galactosidase production reached a plateau. The beta-galactosidase yield had a maximum value at a viable cell density time integral of approximately 8 x 10(6) cells.